Add some olive oil to a frying pan and on a medium heat and then add the onion, after 2 minutes add the chorizo and then after another 2 minutes add the garlic and 2 minutes later add the paprika and thyme.
Add the rice and cook for a minute and then add the sherry and cook until it has all evaporated and then add the tomatoes, tomato puree and the stock. Cover the pan with with a lid a leave to simmer for 15 minutes adding a splash of water if needed.
Stir in the peas and prawns, replace the lid, and cook for a further 5 minutes, or until hot through.
Add the lemon juice and serve along with additional lemon wedges.